Radio frequency (RF) switching devices are used in many applications, such as in wireless communication systems, to selectively pass an RF signal. For switching devices that include field-effect transistors (FETs), a negative bias voltage is required to bias the FETs in an off state. The negative bias voltage is typically generated by a negative voltage generator that includes an oscillator and a charge pump. The oscillator may inject spurs into the RF core of the switching device, thereby causing spurious emissions.